class enc_filebuf.
More...
List of all members.
Public Types
Public Member Functions
Protected Member Functions
-
void __safe_gbump (streamsize __n)
-
void __safe_pbump (streamsize __n)
-
void _M_allocate_internal_buffer ()
-
bool _M_convert_to_external (char_type *, streamsize)
- void _M_create_pback ()
-
void _M_destroy_internal_buffer () throw ()
- void _M_destroy_pback () throw ()
-
int _M_get_ext_pos (__state_type &__state)
-
pos_type _M_seek (off_type __off, ios_base::seekdir __way, __state_type __state)
- void _M_set_buffer (streamsize __off)
-
bool _M_terminate_output ()
- void gbump (int __n)
- virtual void imbue (const locale &__loc)
-
virtual int_type overflow (int_type __c=encoding_char_traits< _CharT >::eof())
- virtual int_type overflow (int_type=traits_type::eof())
- virtual int_type pbackfail (int_type=traits_type::eof())
-
virtual int_type pbackfail (int_type __c=encoding_char_traits< _CharT >::eof())
- void pbump (int __n)
-
virtual pos_type seekoff (off_type __off, ios_base::seekdir __way, ios_base::openmode __mode=ios_base::in|ios_base::out)
- virtual pos_type seekoff (off_type, ios_base::seekdir, ios_base::openmode=ios_base::in|ios_base::out)
- virtual pos_type seekpos (pos_type, ios_base::openmode=ios_base::in|ios_base::out)
-
virtual pos_type seekpos (pos_type __pos, ios_base::openmode __mode=ios_base::in|ios_base::out)
- virtual __streambuf_type * setbuf (char_type *__s, streamsize __n)
- virtual basic_streambuf
< char_type,
encoding_char_traits< _CharT > > * setbuf (char_type *, streamsize)
- void setg (char_type *__gbeg, char_type *__gnext, char_type *__gend)
- void setp (char_type *__pbeg, char_type *__pend)
- virtual streamsize showmanyc ()
- virtual int sync ()
- virtual int_type uflow ()
- virtual int_type underflow ()
-
virtual streamsize xsgetn (char_type *__s, streamsize __n)
- virtual streamsize xsgetn (char_type *__s, streamsize __n)
- virtual streamsize xsputn (const char_type *__s, streamsize __n)
-
virtual streamsize xsputn (const char_type *__s, streamsize __n)
|
|
|
|
Protected Attributes
|
|
Friends
-
__gnu_cxx::__enable_if
< __is_char< _CharT2 >
::__value, _CharT2 * >::__type __copy_move_a2 (istreambuf_iterator< _CharT2 >, istreambuf_iterator< _CharT2 >, _CharT2 *)
-
streamsize __copy_streambufs_eof (__streambuf_type *, __streambuf_type *, bool &)
-
class basic_ios< char_type, traits_type >
-
class basic_istream< char_type, traits_type >
-
class basic_ostream< char_type, traits_type >
-
__gnu_cxx::__enable_if
< __is_char< _CharT2 >
::__value, istreambuf_iterator
< _CharT2 > >::__type find (istreambuf_iterator< _CharT2 >, istreambuf_iterator< _CharT2 >, const _CharT2 &)
-
basic_istream< _CharT2,
_Traits2 > & getline (basic_istream< _CharT2, _Traits2 > &, basic_string< _CharT2, _Traits2, _Alloc > &, _CharT2)
-
class ios_base
-
class istreambuf_iterator< char_type, traits_type >
-
basic_istream< _CharT2,
_Traits2 > & operator>> (basic_istream< _CharT2, _Traits2 > &, _CharT2 *)
-
basic_istream< _CharT2,
_Traits2 > & operator>> (basic_istream< _CharT2, _Traits2 > &, basic_string< _CharT2, _Traits2, _Alloc > &)
-
class ostreambuf_iterator< char_type, traits_type >
Detailed Description
template<typename _CharT>
class __gnu_cxx::enc_filebuf< _CharT >
class enc_filebuf.
Definition at line 42 of file enc_filebuf.h.
Member Typedef Documentation
template<typename _CharT >
template<typename _CharT >
Member Function Documentation
Initializes pback buffers, and moves normal buffers to safety. Assumptions: _M_in_cur has already been moved back
Definition at line 174 of file fstream.
Deactivates pback buffer contents, and restores normal buffer. Assumptions: The pback buffer has only moved forward.
Definition at line 191 of file fstream.
This function sets the pointers of the internal buffer, both get and put areas. Typically:
__off == egptr() - eback() upon underflow/uflow (read mode); __off == 0 upon overflow (write mode); __off == -1 upon open, setbuf, seekoff/pos (uncommitted mode).
NB: epptr() - pbase() == _M_buf_size - 1, since _M_buf_size reflects the actual allocated memory and the last cell is reserved for the overflow char of a full put area.
Definition at line 392 of file fstream.
Closes the currently associated file.
- Returns:
this
on success, NULL on failure
If no file is currently open, this function immediately fails.
If a put buffer area exists, overflow(eof)
is called to flush all the characters. The file is then closed.
If any operations fail, this function also fails.
Access to the get area.
These functions are only available to other protected functions, including derived classes.
- eback() returns the beginning pointer for the input sequence
- gptr() returns the next pointer for the input sequence
- egptr() returns the end pointer for the input sequence
Definition at line 462 of file streambuf.
Access to the get area.
These functions are only available to other protected functions, including derived classes.
- eback() returns the beginning pointer for the input sequence
- gptr() returns the next pointer for the input sequence
- egptr() returns the end pointer for the input sequence
Definition at line 468 of file streambuf.
Access to the put area.
These functions are only available to other protected functions, including derived classes.
- pbase() returns the beginning pointer for the output sequence
- pptr() returns the next pointer for the output sequence
- epptr() returns the end pointer for the output sequence
Definition at line 515 of file streambuf.
Moving the read position.
- Parameters:
-
| n | The delta by which to move. |
This just advances the read position without returning any data.
Definition at line 478 of file streambuf.
Locale access.
- Returns:
- The current locale in effect.
If pubimbue(loc) has been called, then the most recent loc
is returned. Otherwise the global locale in effect at the time of construction is returned.
Definition at line 224 of file streambuf.
Access to the get area.
These functions are only available to other protected functions, including derived classes.
- eback() returns the beginning pointer for the input sequence
- gptr() returns the next pointer for the input sequence
- egptr() returns the end pointer for the input sequence
Definition at line 465 of file streambuf.
Changes translations.
- Parameters:
-
Translations done during I/O which depend on the current locale are changed by this call. The standard adds, Between invocations of this function a class derived from streambuf can safely cache results of calls to locale functions and to members of facets so obtained.
- Note:
- Base class version does nothing.
Reimplemented from std::basic_streambuf< _CharT, encoding_char_traits< _CharT > >.
Looking ahead into the stream.
- Returns:
- The number of characters available.
If a read position is available, returns the number of characters available for reading before the buffer must be refilled. Otherwise returns the derived showmanyc()
.
Definition at line 264 of file streambuf.
Returns true if the external file is open.
Definition at line 224 of file fstream.
Opens an external file.
- Parameters:
-
| s | The name of the file. |
| mode | The open mode flags. |
- Returns:
this
on success, NULL on failure
If a file is already open, this function immediately fails. Otherwise it tries to open the file named s using the flags given in mode.
Table 92, adapted here, gives the relation between openmode combinations and the equivalent fopen() flags. (NB: lines app, in|out|app, in|app, binary|app, binary|in|out|app, and binary|in|app per DR 596) +---------------------------------------------------------+ | ios_base Flag combination stdio equivalent | |binary in out trunc app | +---------------------------------------------------------+ | + w | | + + a | | + a | | + + w | | + r | | + + r+ | | + + + w+ | | + + + a+ | | + + a+ | +---------------------------------------------------------+ | + + wb | | + + + ab | | + + ab | | + + + wb | | + + rb | | + + + r+b | | + + + + w+b | | + + + + a+b | | + + + a+b | +---------------------------------------------------------+
Opens an external file.
- Parameters:
-
| s | The name of the file. |
| mode | The open mode flags. |
- Returns:
this
on success, NULL on failure
Definition at line 277 of file fstream.
Consumes data from the buffer; writes to the controlled sequence.
- Parameters:
-
| c | An additional character to consume. |
- Returns:
- eof() to indicate failure, something else (usually c, or not_eof())
Informally, this function is called when the output buffer is full (or does not exist, as buffering need not actually be done). If a buffer exists, it is consumed, with some effect on the controlled sequence. (Typically, the buffer is written out to the sequence verbatim.) In either case, the character c is also written out, if c is not eof()
.
For a formal definition of this function, see a good text such as Langer & Kreft, or [27.5.2.4.5]/3-7.
A functioning output streambuf can be created by overriding only this function (no buffer area will be used).
- Note:
- Base class version does nothing, returns eof().
Definition at line 748 of file streambuf.
Tries to back up the input sequence.
- Parameters:
-
| c | The character to be inserted back into the sequence. |
- Returns:
- eof() on failure, some other value on success
- Postcondition:
- The constraints of
gptr()
, eback()
, and pptr()
are the same as for underflow()
.
- Note:
- Base class version does nothing, returns eof().
Definition at line 704 of file streambuf.
Access to the put area.
These functions are only available to other protected functions, including derived classes.
- pbase() returns the beginning pointer for the output sequence
- pptr() returns the next pointer for the output sequence
- epptr() returns the end pointer for the output sequence
Definition at line 509 of file streambuf.
Moving the write position.
- Parameters:
-
| n | The delta by which to move. |
This just advances the write position without returning any data.
Definition at line 525 of file streambuf.
Access to the put area.
These functions are only available to other protected functions, including derived classes.
- pbase() returns the beginning pointer for the output sequence
- pptr() returns the next pointer for the output sequence
- epptr() returns the end pointer for the output sequence
Definition at line 512 of file streambuf.
Entry point for imbue().
- Parameters:
-
- Returns:
- The previous locale.
Calls the derived imbue(loc).
Definition at line 207 of file streambuf.
Entry point for imbue().
- Parameters:
-
- Returns:
- The previous locale.
Calls the derived imbue(loc).
Definition at line 241 of file streambuf.
Entry point for imbue().
- Parameters:
-
- Returns:
- The previous locale.
Calls the derived imbue(loc).
Definition at line 246 of file streambuf.
Entry points for derived buffer functions.
The public versions of pubfoo
dispatch to the protected derived foo
member functions, passing the arguments (if any) and returning the result unchanged.
Definition at line 237 of file streambuf.
Entry point for imbue().
- Parameters:
-
- Returns:
- The previous locale.
Calls the derived imbue(loc).
Definition at line 251 of file streambuf.
Getting the next character.
- Returns:
- The next character, or eof.
If the input read position is available, returns that character and increments the read pointer, otherwise calls and returns uflow()
.
Definition at line 296 of file streambuf.
Alters the stream positions.
Each derived class provides its own appropriate behavior.
- Note:
- Base class version does nothing, returns a
pos_type
that represents an invalid stream position.
Definition at line 582 of file streambuf.
Alters the stream positions.
Each derived class provides its own appropriate behavior.
- Note:
- Base class version does nothing, returns a
pos_type
that represents an invalid stream position.
Definition at line 594 of file streambuf.
Setting the three read area pointers.
- Parameters:
-
| gbeg | A pointer. |
| gnext | A pointer. |
| gend | A pointer. |
- Postcondition:
- gbeg ==
eback()
, gnext == gptr()
, and gend == egptr()
Definition at line 489 of file streambuf.
Setting the three write area pointers.
- Parameters:
-
| pbeg | A pointer. |
| pend | A pointer. |
- Postcondition:
- pbeg ==
pbase()
, pbeg == pptr()
, and pend == epptr()
Definition at line 535 of file streambuf.
Getting the next character.
- Returns:
- The next character, or eof.
If the input read position is available, returns that character, otherwise calls and returns underflow()
. Does not move the read position after fetching the character.
Definition at line 318 of file streambuf.
Entry point for xsgetn.
- Parameters:
-
| s | A buffer area. |
| n | A count. |
Returns xsgetn(s,n). The effect is to fill s[0] through s[n-1] with characters from the input sequence, if possible.
Definition at line 337 of file streambuf.
Investigating the data available.
- Returns:
- An estimate of the number of characters available in the input sequence, or -1.
If it returns a positive value, then successive calls to underflow()
will not return traits::eof()
until at least that number of characters have been supplied. If showmanyc()
returns -1, then calls to underflow()
or uflow()
will fail. [27.5.2.4.3]/1
- Note:
- Base class version does nothing, returns zero.
-
The standard adds that the intention is not only that the calls [to underflow or uflow] will not return
eof()
but that they will return immediately.
-
The standard adds that the morphemes of
showmanyc
are es-how-many-see, not show-manic.
Reimplemented from std::basic_streambuf< _CharT, encoding_char_traits< _CharT > >.
Getting the next character.
- Returns:
- The next character, or eof.
Calls sbumpc()
, and if that function returns traits::eof()
, so does this function. Otherwise, sgetc()
.
Definition at line 278 of file streambuf.
Pushing characters back into the input stream.
- Parameters:
-
| c | The character to push back. |
- Returns:
- The previous character, if possible.
Similar to sungetc(), but c is pushed onto the stream instead of the previous character. If successful, the next character fetched from the input stream will be c.
Definition at line 352 of file streambuf.
Entry point for all single-character output functions.
- Parameters:
-
- Returns:
- c, if possible.
One of two public output functions.
If a write position is available for the output sequence (i.e., the buffer is not full), stores c in that position, increments the position, and returns traits::to_int_type(c)
. If a write position is not available, returns overflow(c)
.
Definition at line 404 of file streambuf.
Entry point for all single-character output functions.
- Parameters:
-
| s | A buffer read area. |
| n | A count. |
One of two public output functions.
Returns xsputn(s,n). The effect is to write s[0] through s[n-1] to the output sequence, if possible.
Definition at line 430 of file streambuf.
Moving backwards in the input stream.
- Returns:
- The previous character, if possible.
If a putback position is available, this function decrements the input pointer and returns that character. Otherwise, calls and returns pbackfail(). The effect is to unget the last character gotten.
Definition at line 377 of file streambuf.
Synchronizes the buffer arrays with the controlled sequences.
- Returns:
- -1 on failure.
Each derived class provides its own appropriate behavior, including the definition of failure.
- Note:
- Base class version does nothing, returns zero.
Reimplemented from std::basic_streambuf< _CharT, encoding_char_traits< _CharT > >.
Fetches more data from the controlled sequence.
- Returns:
- The first character from the pending sequence.
Informally, this function does the same thing as underflow()
, and in fact is required to call that function. It also returns the new character, like underflow()
does. However, this function also moves the read position forward by one.
Definition at line 680 of file streambuf.
Fetches more data from the controlled sequence.
- Returns:
- The first character from the pending sequence.
Informally, this function is called when the input buffer is exhausted (or does not exist, as buffering need not actually be done). If a buffer exists, it is refilled. In either case, the next available character is returned, or traits::eof()
to indicate a null pending sequence.
For a formal definition of the pending sequence, see a good text such as Langer & Kreft, or [27.5.2.4.3]/7-14.
A functioning input streambuf can be created by overriding only this function (no buffer area will be used). For an example, see http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt11ch25.html
- Note:
- Base class version does nothing, returns eof().
Reimplemented from std::basic_streambuf< _CharT, encoding_char_traits< _CharT > >.
Multiple character extraction.
- Parameters:
-
| s | A buffer area. |
| n | Maximum number of characters to assign. |
- Returns:
- The number of characters assigned.
Fills s[0] through s[n-1] with characters from the input sequence, as if by sbumpc()
. Stops when either n characters have been copied, or when traits::eof()
would be copied.
It is expected that derived classes provide a more efficient implementation by overriding this definition.
Multiple character insertion.
- Parameters:
-
| s | A buffer area. |
| n | Maximum number of characters to write. |
- Returns:
- The number of characters written.
Writes s[0] through s[n-1] to the output sequence, as if by sputc()
. Stops when either n characters have been copied, or when sputc()
would return traits::eof()
.
It is expected that derived classes provide a more efficient implementation by overriding this definition.
Member Data Documentation
Pointer to the beginning of internal buffer.
Definition at line 111 of file fstream.
Current locale setting.
Definition at line 190 of file streambuf.
Actual size of internal buffer. This number is equal to the size of the put area + 1 position, reserved for the overflow char of a full area.
Definition at line 118 of file fstream.
Buffer for external characters. Used for input when codecvt::always_noconv() == false. When valid, this corresponds to eback().
Definition at line 153 of file fstream.
Size of buffer held by _M_ext_buf.
Definition at line 158 of file fstream.
Pointers into the buffer held by _M_ext_buf that delimit a subsequence of bytes that have been read but not yet converted. When valid, _M_ext_next corresponds to egptr().
Definition at line 165 of file fstream.
This is based on _IO_FILE, just reordered to be more consistent, and is intended to be the most minimal abstraction for an internal buffer.
- get == input == read
- put == output == write
Definition at line 182 of file streambuf.
Entry point for imbue().
- Parameters:
-
- Returns:
- The previous locale.
Calls the derived imbue(loc).
Definition at line 183 of file streambuf.
Entry point for imbue().
- Parameters:
-
- Returns:
- The previous locale.
Calls the derived imbue(loc).
Definition at line 184 of file streambuf.
Place to stash in || out || in | out settings for current filebuf.
Definition at line 96 of file fstream.
Entry point for imbue().
- Parameters:
-
- Returns:
- The previous locale.
Calls the derived imbue(loc).
Definition at line 185 of file streambuf.
Entry point for imbue().
- Parameters:
-
- Returns:
- The previous locale.
Calls the derived imbue(loc).
Definition at line 186 of file streambuf.
Entry point for imbue().
- Parameters:
-
- Returns:
- The previous locale.
Calls the derived imbue(loc).
Definition at line 187 of file streambuf.
Necessary bits for putback buffer management.
- Note:
- pbacks of over one character are not currently supported.
Definition at line 139 of file fstream.
Necessary bits for putback buffer management.
- Note:
- pbacks of over one character are not currently supported.
Definition at line 140 of file fstream.
Necessary bits for putback buffer management.
- Note:
- pbacks of over one character are not currently supported.
Definition at line 141 of file fstream.
Necessary bits for putback buffer management.
- Note:
- pbacks of over one character are not currently supported.
Definition at line 142 of file fstream.
_M_reading == false && _M_writing == false for uncommitted mode; _M_reading == true for read mode; _M_writing == true for write mode;
NB: _M_reading == true && _M_writing == true is unused.
Definition at line 130 of file fstream.
The documentation for this class was generated from the following file: